Different electromagnetic energy sources that output different wavelengths of light can be used together in performing various procedures. In the dental field, for example, different wavelengths of light can be effective in performing various aspects of a dental procedure. In one system, electromagnetic radiation of a first wavelength is applied in a teeth-whitening procedure (e.g., output from a laser or laser diode within a wavelength range of approximately 390 nm-480 nm), and electromagnetic radiation of a second wavelength is applied in a gum treatment procedure (e.g., output from a laser or laser diode within a wavelength range of approximately 620 nm-680 nm). The electromagnetic radiation of the different wavelengths may be output simultaneously via a single device. A graphical user interface for controlling the plurality of electromagnetic energy sources used in the device may be desirable.